@article{19998, abstract = {nspired by Richard Feynman’s 1959 lecture and the 1966 film Fantastic Voyage, the field of micro/nanorobots has evolved from science fiction to reality, with significant advancements in biomedical and environmental applications. Despite the rapid progress, the deployment of functional micro/nanorobots remains limited. This review of the technology roadmap identifies key challenges hindering their widespread use, focusing on propulsion mechanisms, fundamental theoretical aspects, collective behavior, material design, and embodied intelligence. We explore the current state of micro/nanorobot technology, with an emphasis on applications in biomedicine, environmental remediation, analytical sensing, and other industrial technological aspects. Additionally, we analyze issues related to scaling up production, commercialization, and regulatory frameworks that are crucial for transitioning from research to practical applications. We also emphasize the need for interdisciplinary collaboration to address both technical and nontechnical challenges, such as sustainability, ethics, and business considerations. Finally, we propose a roadmap for future research to accelerate the development of micro/nanorobots, positioning them as essential tools for addressing grand challenges and enhancing the quality of life.}, author = {Ju, Xiaohui and Chen, Chuanrui and Oral, Cagatay M. and Sevim, Semih and Golestanian, Ramin and Sun, Mengmeng and Bouzari, Negin and Lin, Xiankun and Urso, Mario and Nam, Jong Seok and Cho, Yujang and Peng, Xia and Landers, Fabian C. and Yang, Shihao and Adibi, Azin and Taz, Nahid and Wittkowski, Raphael and Ahmed, Daniel and Wang, Wei and Magdanz, Veronika and Medina-Sánchez, Mariana and Guix, Maria and Bari, Naimat and Behkam, Bahareh and Kapral, Raymond and Huang, Yaxin and Tang, Jinyao and Wang, Ben and Morozov, Konstantin and Leshansky, Alexander and Abbasi, Sarmad Ahmad and Choi, Hongsoo and Ghosh, Subhadip and Borges Fernandes, Bárbara and Battaglia, Giuseppe and Fischer, Peer and Ghosh, Ambarish and Jurado Sánchez, Beatriz and Escarpa, Alberto and Martinet, Quentin and Palacci, Jérémie A and Lauga, Eric and Moran, Jeffrey and Ramos-Docampo, Miguel A. and Städler, Brigitte and Herrera Restrepo, Ramón Santiago and Yossifon, Gilad and Nicholas, James D. and Ignés-Mullol, Jordi and Puigmartí-Luis, Josep and Liu, Yutong and Zarzar, Lauren D. and Shields, C. Wyatt and Li, Longqiu and Li, Shanshan and Ma, Xing and Gracias, David H. and Velev, Orlin and Sánchez, Samuel and Esplandiu, Maria Jose and Simmchen, Juliane and Lobosco, Antonio and Misra, Sarthak and Wu, Zhiguang and Li, Jinxing and Kuhn, Alexander and Nourhani, Amir and Maric, Tijana and Xiong, Ze and Aghakhani, Amirreza and Mei, Yongfeng and Tu, Yingfeng and Peng, Fei and Diller, Eric and Sakar, Mahmut Selman and Sen, Ayusman and Law, Junhui and Sun, Yu and Pena-Francesch, Abdon and Villa, Katherine and Li, Huaizhi and Fan, Donglei Emma and Liang, Kang and Huang, Tony Jun and Chen, Xiang-Zhong and Tang, Songsong and Zhang, Xueji and Cui, Jizhai and Wang, Hong and Gao, Wei and Kumar Bandari, Vineeth and Schmidt, Oliver G. and Wu, Xianghua and Guan, Jianguo and Sitti, Metin and Nelson, Bradley J. and Pané, Salvador and Zhang, Li and Shahsavan, Hamed and He, Qiang and Kim, Il-Doo and Wang, Joseph and Pumera, Martin}, issn = {1936-086X}, journal = {ACS Nano}, number = {27}, pages = {24174--24334}, publisher = {American Chemical Society}, title = {{Technology roadmap of micro/nanorobots}}, doi = {10.1021/acsnano.5c03911}, volume = {19}, year = {2025}, } @article{20329, abstract = {Nanocrystals (NCs) of various compositions have made important contributions to science and technology, with their impact recognized by the 2023 Nobel Prize in Chemistry for the discovery and synthesis of semiconductor quantum dots (QDs). Over four decades of research into NCs has led to numerous advancements in diverse fields, such as optoelectronics, catalysis, energy, medicine, and recently, quantum information and computing. The last 10 years since the predecessor perspective “Prospect of Nanoscience with Nanocrystals” was published in ACS Nano have seen NC research continuously evolve, yielding critical advances in fundamental understanding and practical applications. Mechanistic insights into NC formation have translated into precision control over NC size, shape, and composition. Emerging synthesis techniques have broadened the landscape of compounds obtainable in colloidal NC form. Sophistication in surface chemistry, jointly bolstered by theoretical models and experimental findings, has facilitated refined control over NC properties and represents a trusted gateway to enhanced NC stability and processability. The assembly of NCs into superlattices, along with two-dimensional (2D) photolithography and three-dimensional (3D) printing, has expanded their utility in creating materials with tailored properties. Applications of NCs are also flourishing, consolidating progress in fields targeted early on, such as optoelectronics and catalysis, and extending into areas ranging from quantum technology to phase-change memories. In this perspective, we review the extensive progress in research on NCs over the past decade and highlight key areas where future research may bring further breakthroughs.}, author = {Ibáñez, Maria and Boehme, Simon C. and Buonsanti, Raffaella and De Roo, Jonathan and Milliron, Delia J. and Ithurria, Sandrine and Rogach, Andrey L. and Cabot, Andreu and Yarema, Maksym and Cossairt, Brandi M. and Reiss, Peter and Talapin, Dmitri V. and Protesescu, Loredana and Hens, Zeger and Infante, Ivan and Bodnarchuk, Maryna I. and Ye, Xingchen and Wang, Yuanyuan and Zhang, Hao and Lhuillier, Emmanuel and Klimov, Victor I. and Utzat, Hendrik and Rainò, Gabriele and Kagan, Cherie R. and Cargnello, Matteo and Son, Jae Sung and Kovalenko, Maksym V.}, issn = {1936-086X}, journal = {ACS Nano}, number = {36}, pages = { 31969–32051}, publisher = {American Chemical Society}, title = {{Prospects of nanoscience with nanocrystals: 2025 edition}}, doi = {10.1021/acsnano.5c07838}, volume = {19}, year = {2025}, } @article{20426, abstract = {SnTe has attracted significant research interest as a lead-free alternative to PbTe; however, its intrinsically high hole concentration results in an undesirably low Seebeck coefficient and elevated electronic thermal conductivity, thus significantly limiting its thermoelectric (TE) performance. Herein, we present a cost-effective, binary thiol-amine-mediated colloidal synthesis method to synthesize Bi-doped SnTe nanoparticles, eliminating the use of tri-n-octylphosphine-based precursors. The introduction of an electron-rich Bi dopant reduces the hole concentration and increases the Seebeck coefficient. Furthermore, post-synthetic surface treatment with chalcogenidocadmate complexes promotes atomic interdiffusion during annealing and consolidation, leading to compositional redistribution and modulation of the electronic band structure. Density functional theory (DFT) calculations reveal that co-modification via Bi doping and CdSe-derived chalcogen incorporation reduces the energy offset at the valence band maxima from 0.30 eV to 0.10 eV, thereby enhancing valence band degeneracy. The synergistic structural and electronic band structure modulations produce an SnTe-based material with a record high power factor of 2.1 mW m–1 K–2 at 900 K, a maximum TE figure of merit (zT) of 1.2, and a promising theoretical conversion efficiency of 8.3%. This study reports a versatile and scalable colloidal synthesis strategy that integrates hierarchical structural modulation with electronic band engineering, offering a synergistic route to significantly enhance the TE performance.}, author = {Meng, Weite and Xu, Lixiang and Lu, Shaoqing and Li, Mingquan and Li, Mengyao and Zhang, Yu and Wang, Qingyue and Wang, Wen Jun and Huo, Siqi and Bañares, Miguel A. and Martin-Gonzalez, Marisol and Ibáñez, Maria and Cabot, Andreu and Hong, Min and Liu, Yu and Lim, Khak Ho}, issn = {1936-086X}, journal = {ACS Nano}, number = {38}, pages = {34395--34407}, publisher = {American Chemical Society}, title = {{Thiol-Amine complexes for the synthesis and surface engineering of SnTe nanomaterials toward high thermoelectric performance}}, doi = {10.1021/acsnano.5c12627}, volume = {19}, year = {2025}, } @article{19441, abstract = {Catalytic microswimmers convert the chemical energy from fuel into motion. They sustain chemical gradients and fluid flows that propel them by phoresis. This leads to unconventional behavior and collective dynamics, such as self-organization into complex structures. Characterizing the nonequilibrium interactions of microswimmers is crucial for advancing our understanding of active systems. However, this remains a challenge owing to the importance of fluctuations at the microscale and the difficulty in disentangling the different contributions to the interactions. Here, we show a massive dependence of the nonequilibrium interactions on the shape of catalytic microswimmers. We perform tracking experiments at high throughput to map interactions between nanocolloidal tracers and dimeric microswimmers of various aspect ratios. Our method leverages dual tracers with differing phoretic mobilities to quantitatively disentangle phoretic motion from hydrodynamic advection. This approach is validated through experiments on single chemically active sites and on immobilized catalytic microswimmers. We further investigate the activity-driven interactions of free microswimmers and directly measure their phoretic interactions. When compared to standard models, our findings highlight the important role of osmotic flows for microswimmers near surfaces and reveal an enhanced contribution of hydrodynamic advection relative to phoretic motion as the size of the microswimmer increases. Our study provides robust measurements of the nonequilibrium interactions from catalytic microswimmers and lays the groundwork for a realistic description of active systems.}, author = {Carrasco, Celso and Martinet, Quentin and Shen, Zaiyi and Lintuvuori, Juho and Palacci, Jérémie A and Aubret, Antoine}, issn = {1936-086X}, journal = {ACS Nano}, number = {11}, pages = {11133--11145}, publisher = {American Chemical Society}, title = {{Characterization of nonequilibrium interactions of catalytic microswimmers using phoretically responsive nanotracers}}, doi = {10.1021/acsnano.4c18078}, volume = {19}, year = {2025}, } @article{19629, abstract = {The SiOx anode exhibits a high specific capacity and commendable durability for lithium-ion batteries (LIBs). However, its practical application is hindered by significant volumetric fluctuations during lithiation/delithiation, alongside a metastable nature, which induces mechanical instability and irreversible lithium consumption, ultimately impairing long-term capacity retention in full-battery cell configurations. In this study, we present a phase-engineering approach designed to improve the structural stability of SiOx anodes for LIB applications. By incorporating lithium fluoride, amorphous SiOx undergoes partial transformation into a quartz-like phase, which enhances mechanical integrity and mitigates irreversible lithium loss. This modified anode demonstrates significantly improved stability and prolonged cycle lifespan. Through a combination of multiscale simulations and in situ characterizations, we elucidate the stabilization mechanisms conferred by the quartz phase, providing critical insights into the role of SiOx’s crystal structure in influencing degradation pathways. This work introduces an accessible and efficient method for controlling the crystallinity of SiOx, offering a practical solution to enhance the durability of high-energy-density LIBs.}, author = {Li, Jing and Zeng, Guifang and Horta, Sharona and Martínez-Alanis, Paulina R. and Jacas Biendicho, Jordi and Ibáñez, Maria and Xu, Bingang and Ci, Lijie and Cabot, Andreu and Sun, Qing}, issn = {1936-086X}, journal = {ACS Nano}, number = {16}, pages = {16096--16109}, publisher = {American Chemical Society}, title = {{Crystallographic engineering in micron-sized SiOx anode material toward stable high-energy-density Lithium-Ion batteries}}, doi = {10.1021/acsnano.5c03074}, volume = {19}, year = {2025}, } @article{21524, abstract = {In X-ray tubes, more than 99% of the kilowatts of power supplied to generate X-rays via bremsstrahlung is lost as heat in the anode. Therefore, thermal management is a critical barrier to the development of more powerful X-ray tubes with higher brightness and spatial coherence, which are needed to translate imaging modalities such as phase-contrast imaging to the clinic. In rotating anode X-ray tubes, the most common design, thermal radiation is a bottleneck that prevents efficient cooling of the anode─the hottest part of the device by far. We predict that nanophotonic patterning of the anode of an X-ray tube enhances heat dissipation via thermal radiation, enabling it to operate at higher powers without an increase in temperature. The focal spot size, which is related to the spatial coherence of generated X-rays, can also be reduced at a constant temperature. A major advantage of our “nanophotonic thermal management” approach is that in principle, it allows complete control over the spectrum and direction of thermal radiation, which can lead to optimal thermal routing and improved performance.}, author = {Pajovic, Simo and Roques-Carmes, Charles and Choi, Seou and Kooi, Steven E. and Gupta, Rajiv and Zalis, Michael E. and Čelanović, Ivan and Soljačić, Marin}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {X-ray tubes, thermal management, nanophotonics, thermal radiation, X-ray imaging, high-temperature}, number = {35}, pages = {31363--31370}, publisher = {American Chemical Society}, title = {{Nanophotonic thermal management in X-ray tubes}}, doi = {10.1021/acsnano.5c05186}, volume = {19}, year = {2025}, } @article{17125, abstract = {We explore the potential of nanocrystals (a term used equivalently to nanoparticles) as building blocks for nanomaterials, and the current advances and open challenges for fundamental science developments and applications. Nanocrystal assemblies are inherently multiscale, and the generation of revolutionary material properties requires a precise understanding of the relationship between structure and function, the former being determined by classical effects and the latter often by quantum effects. With an emphasis on theory and computation, we discuss challenges that hamper current assembly strategies and to what extent nanocrystal assemblies represent thermodynamic equilibrium or kinetically trapped metastable states. We also examine dynamic effects and optimization of assembly protocols. Finally, we discuss promising material functions and examples of their realization with nanocrystal assemblies.}, author = {Bassani, Carlos L. and Van Anders, Greg and Banin, Uri and Baranov, Dmitry and Chen, Qian and Dijkstra, Marjolein and Dimitriyev, Michael S. and Efrati, Efi and Faraudo, Jordi and Gang, Oleg and Gaston, Nicola and Golestanian, Ramin and Guerrero-Garcia, G. Ivan and Gruenwald, Michael and Haji-Akbari, Amir and Ibáñez, Maria and Karg, Matthias and Kraus, Tobias and Lee, Byeongdu and Van Lehn, Reid C. and Macfarlane, Robert J. and Mognetti, Bortolo M. and Nikoubashman, Arash and Osat, Saeed and Prezhdo, Oleg V. and Rotskoff, Grant M. and Saiz, Leonor and Shi, An Chang and Skrabalak, Sara and Smalyukh, Ivan I. and Tagliazucchi, Mario and Talapin, Dmitri V. and Tkachenko, Alexei V. and Tretiak, Sergei and Vaknin, David and Widmer-Cooper, Asaph and Wong, Gerard C.L. and Ye, Xingchen and Zhou, Shan and Rabani, Eran and Engel, Michael and Travesset, Alex}, issn = {1936-086X}, journal = {ACS Nano}, number = {23}, pages = {14791--14840}, publisher = {American Chemical Society}, title = {{Nanocrystal assemblies: Current advances and open problems}}, doi = {10.1021/acsnano.3c10201}, volume = {18}, year = {2024}, } @article{17239, abstract = {Collagen is the most abundant protein in tissue scaffolds in live organisms. Collagen can self-assemble in vitro, which has led to a number of biotechnological and biomedical applications. To understand the dominant factors that participate in the formation of collagen nanostructures, here we study in real time and with nanoscale resolution the disassembly and reassembly of collagens. We implement a high-speed force microscope, which provides in situ high spatiotemporal resolution images of collagen nanostructures under changing pH conditions. The disassembly and reassembly are dominated by the electrostatic interactions among amino-acid residues of different molecules. Acidic conditions favor disassembly by neutralizing negatively charged residues. The process sets a net repulsive force between collagen molecules. A neutral pH favors the presence of negative and positively charged residues along the collagen molecules, which promotes their electrostatic attraction. Molecular dynamics simulations reproduce the experimental behavior and validate the electrostatic-based model of the disassembly and reassembly processes.}, author = {Garcia-Sacristan, Clara and Gisbert, Victor G. and Klein, Kevin and Šarić, Anđela and Garcia, Ricardo}, issn = {1936-086X}, journal = {ACS Nano}, number = {28}, pages = {18485--18492}, publisher = {American Chemical Society}, title = {{In operando imaging electrostatic-driven disassembly and reassembly of collagen nanostructures}}, doi = {10.1021/acsnano.4c03839}, volume = {18}, year = {2024}, } @article{12915, abstract = {Cu2–xS and Cu2–xSe have recently been reported as promising thermoelectric (TE) materials for medium-temperature applications. In contrast, Cu2–xTe, another member of the copper chalcogenide family, typically exhibits low Seebeck coefficients that limit its potential to achieve a superior thermoelectric figure of merit, zT, particularly in the low-temperature range where this material could be effective. To address this, we investigated the TE performance of Cu1.5–xTe–Cu2Se nanocomposites by consolidating surface-engineered Cu1.5Te nanocrystals. This surface engineering strategy allows for precise adjustment of Cu/Te ratios and results in a reversible phase transition at around 600 K in Cu1.5–xTe–Cu2Se nanocomposites, as systematically confirmed by in situ high-temperature X-ray diffraction combined with differential scanning calorimetry analysis. The phase transition leads to a conversion from metallic-like to semiconducting-like TE properties. Additionally, a layer of Cu2Se generated around Cu1.5–xTe nanoparticles effectively inhibits Cu1.5–xTe grain growth, minimizing thermal conductivity and decreasing hole concentration. These properties indicate that copper telluride based compounds have a promising thermoelectric potential, translated into a high dimensionless zT of 1.3 at 560 K.}, author = {Xing, Congcong and Zhang, Yu and Xiao, Ke and Han, Xu and Liu, Yu and Nan, Bingfei and Ramon, Maria Garcia and Lim, Khak Ho and Li, Junshan and Arbiol, Jordi and Poudel, Bed and Nozariasbmarz, Amin and Li, Wenjie and Ibáñez, Maria and Cabot, Andreu}, issn = {1936-086X}, journal = {ACS Nano}, number = {9}, pages = {8442--8452}, publisher = {American Chemical Society}, title = {{Thermoelectric performance of surface-engineered Cu1.5–xTe–Cu2Se nanocomposites}}, doi = {10.1021/acsnano.3c00495}, volume = {17}, year = {2023}, } @article{13235, abstract = {AgSbSe2 is a promising thermoelectric (TE) p-type material for applications in the middle-temperature range. AgSbSe2 is characterized by relatively low thermal conductivities and high Seebeck coefficients, but its main limitation is moderate electrical conductivity. Herein, we detail an efficient and scalable hot-injection synthesis route to produce AgSbSe2 nanocrystals (NCs). To increase the carrier concentration and improve the electrical conductivity, these NCs are doped with Sn2+ on Sb3+ sites. Upon processing, the Sn2+ chemical state is conserved using a reducing NaBH4 solution to displace the organic ligand and anneal the material under a forming gas flow. The TE properties of the dense materials obtained from the consolidation of the NCs using a hot pressing are then characterized. The presence of Sn2+ ions replacing Sb3+ significantly increases the charge carrier concentration and, consequently, the electrical conductivity. Opportunely, the measured Seebeck coefficient varied within a small range upon Sn doping. The excellent performance obtained when Sn2+ ions are prevented from oxidation is rationalized by modeling the system. Calculated band structures disclosed that Sn doping induces convergence of the AgSbSe2 valence bands, accounting for an enhanced electronic effective mass. The dramatically enhanced carrier transport leads to a maximized power factor for AgSb0.98Sn0.02Se2 of 0.63 mW m–1 K–2 at 640 K. Thermally, phonon scattering is significantly enhanced in the NC-based materials, yielding an ultralow thermal conductivity of 0.3 W mK–1 at 666 K. Overall, a record-high figure of merit (zT) is obtained at 666 K for AgSb0.98Sn0.02Se2 at zT = 1.37, well above the values obtained for undoped AgSbSe2, at zT = 0.58 and state-of-art Pb- and Te-free materials, which makes AgSb0.98Sn0.02Se2 an excellent p-type candidate for medium-temperature TE applications.}, author = {Liu, Yu and Li, Mingquan and Wan, Shanhong and Lim, Khak Ho and Zhang, Yu and Li, Mengyao and Li, Junshan and Ibáñez, Maria and Hong, Min and Cabot, Andreu}, issn = {1936-086X}, journal = {ACS Nano}, number = {12}, pages = {11923–11934}, publisher = {American Chemical Society}, title = {{Surface chemistry and band engineering in AgSbSe₂: Toward high thermoelectric performance}}, doi = {10.1021/acsnano.3c03541}, volume = {17}, year = {2023}, } @article{13346, abstract = {The self-assembly of nanoparticles driven by small molecules or ions may produce colloidal superlattices with features and properties reminiscent of those of metals or semiconductors. However, to what extent the properties of such supramolecular crystals actually resemble those of atomic materials often remains unclear. Here, we present coarse-grained molecular simulations explicitly demonstrating how a behavior evocative of that of semiconductors may emerge in a colloidal superlattice. As a case study, we focus on gold nanoparticles bearing positively charged groups that self-assemble into FCC crystals via mediation by citrate counterions. In silico ohmic experiments show how the dynamically diverse behavior of the ions in different superlattice domains allows the opening of conductive ionic gates above certain levels of applied electric fields. The observed binary conductive/nonconductive behavior is reminiscent of that of conventional semiconductors, while, at a supramolecular level, crossing the “band gap” requires a sufficient electrostatic stimulus to break the intermolecular interactions and make ions diffuse throughout the superlattice’s cavities.}, author = {Lionello, Chiara and Perego, Claudio and Gardin, Andrea and Klajn, Rafal and Pavan, Giovanni M.}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {General Physics and Astronomy, General Engineering, General Materials Science}, number = {1}, pages = {275--287}, publisher = {American Chemical Society}, title = {{Supramolecular semiconductivity through emerging ionic gates in ion–nanoparticle superlattices}}, doi = {10.1021/acsnano.2c07558}, volume = {17}, year = {2023}, } @article{10042, abstract = {SnSe has emerged as one of the most promising materials for thermoelectric energy conversion due to its extraordinary performance in its single-crystal form and its low-cost constituent elements. However, to achieve an economic impact, the polycrystalline counterpart needs to replicate the performance of the single crystal. Herein, we optimize the thermoelectric performance of polycrystalline SnSe produced by consolidating solution-processed and surface-engineered SnSe particles. In particular, the SnSe particles are coated with CdSe molecular complexes that crystallize during the sintering process, forming CdSe nanoparticles. The presence of CdSe nanoparticles inhibits SnSe grain growth during the consolidation step due to Zener pinning, yielding a material with a high density of grain boundaries. Moreover, the resulting SnSe–CdSe nanocomposites present a large number of defects at different length scales, which significantly reduce the thermal conductivity. The produced SnSe–CdSe nanocomposites exhibit thermoelectric figures of merit up to 2.2 at 786 K, which is among the highest reported for solution-processed SnSe.}, author = {Liu, Yu and Calcabrini, Mariano and Yu, Yuan and Lee, Seungho and Chang, Cheng and David, Jérémy and Ghosh, Tanmoy and Spadaro, Maria Chiara and Xie, Chenyang and Cojocaru-Mirédin, Oana and Arbiol, Jordi and Ibáñez, Maria}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {tin selenide, nanocomposite, grain growth, Zener pinning, thermoelectricity, annealing, solution processing}, number = {1}, pages = {78--88}, publisher = {American Chemical Society }, title = {{Defect engineering in solution-processed polycrystalline SnSe leads to high thermoelectric performance}}, doi = {10.1021/acsnano.1c06720}, volume = {16}, year = {2022}, } @article{9235, abstract = {Cu2–xS has become one of the most promising thermoelectric materials for application in the middle-high temperature range. Its advantages include the abundance, low cost, and safety of its elements and a high performance at relatively elevated temperatures. However, stability issues limit its operation current and temperature, thus calling for the optimization of the material performance in the middle temperature range. Here, we present a synthetic protocol for large scale production of covellite CuS nanoparticles at ambient temperature and atmosphere, and using water as a solvent. The crystal phase and stoichiometry of the particles are afterward tuned through an annealing process at a moderate temperature under inert or reducing atmosphere. While annealing under argon results in Cu1.8S nanopowder with a rhombohedral crystal phase, annealing in an atmosphere containing hydrogen leads to tetragonal Cu1.96S. High temperature X-ray diffraction analysis shows the material annealed in argon to transform to the cubic phase at ca. 400 K, while the material annealed in the presence of hydrogen undergoes two phase transitions, first to hexagonal and then to the cubic structure. The annealing atmosphere, temperature, and time allow adjustment of the density of copper vacancies and thus tuning of the charge carrier concentration and material transport properties. In this direction, the material annealed under Ar is characterized by higher electrical conductivities but lower Seebeck coefficients than the material annealed in the presence of hydrogen. By optimizing the charge carrier concentration through the annealing time, Cu2–xS with record figures of merit in the middle temperature range, up to 1.41 at 710 K, is obtained. We finally demonstrate that this strategy, based on a low-cost and scalable solution synthesis process, is also suitable for the production of high performance Cu2–xS layers using high throughput and cost-effective printing technologies.}, author = {Li, Mengyao and Liu, Yu and Zhang, Yu and Han, Xu and Zhang, Ting and Zuo, Yong and Xie, Chenyang and Xiao, Ke and Arbiol, Jordi and Llorca, Jordi and Ibáñez, Maria and Liu, Junfeng and Cabot, Andreu}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {General Engineering, General Physics and Astronomy, General Materials Science}, number = {3}, pages = {4967–4978}, publisher = {American Chemical Society }, title = {{Effect of the annealing atmosphere on crystal phase and thermoelectric properties of copper sulfide}}, doi = {10.1021/acsnano.0c09866}, volume = {15}, year = {2021}, } @article{9829, abstract = {In 2020, many in-person scientific events were canceled due to the COVID-19 pandemic, creating a vacuum in networking and knowledge exchange between scientists. To fill this void in scientific communication, a group of early career nanocrystal enthusiasts launched the virtual seminar series, News in Nanocrystals, in the summer of 2020. By the end of the year, the series had attracted over 850 participants from 46 countries. In this Nano Focus, we describe the process of organizing the News in Nanocrystals seminar series; discuss its growth, emphasizing what the organizers have learned in terms of diversity and accessibility; and provide an outlook for the next steps and future opportunities. This summary and analysis of experiences and learned lessons are intended to inform the broader scientific community, especially those who are looking for avenues to continue fostering discussion and scientific engagement virtually, both during the pandemic and after.}, author = {Baranov, Dmitry and Šverko, Tara and Moot, Taylor and Keller, Helena R. and Klein, Megan D. and Vishnu, E. K. and Balazs, Daniel and Shulenberger, Katherine E.}, issn = {1936-086X}, journal = {ACS Nano}, number = {7}, pages = {10743–10747}, publisher = {American Chemical Society}, title = {{News in Nanocrystals seminar: Self-assembly of early career researchers toward globally accessible nanoscience}}, doi = {10.1021/acsnano.1c03276}, volume = {15}, year = {2021}, } @article{14299, abstract = {DNA origami nano-objects are usually designed around generic single-stranded “scaffolds”. Many properties of the target object are determined by details of those generic scaffold sequences. Here, we enable designers to fully specify the target structure not only in terms of desired 3D shape but also in terms of the sequences used. To this end, we built design tools to construct scaffold sequences de novo based on strand diagrams, and we developed scalable production methods for creating design-specific scaffold strands with fully user-defined sequences. We used 17 custom scaffolds having different lengths and sequence properties to study the influence of sequence redundancy and sequence composition on multilayer DNA origami assembly and to realize efficient one-pot assembly of multiscaffold DNA origami objects. Furthermore, as examples for functionalized scaffolds, we created a scaffold that enables direct, covalent cross-linking of DNA origami via UV irradiation, and we built DNAzyme-containing scaffolds that allow postfolding DNA origami domain separation.}, author = {FAS, Engelhardt and Praetorius, Florian M and Wachauf, CH and Brüggenthies, G and Kohler, F and Kick, B and Kadletz, KL and Pham, PN and Behler, KL and Gerling, T and Dietz, H}, issn = {1936-086x}, journal = {ACS Nano}, number = {5}, pages = {5015--5027}, publisher = {ACS Publications}, title = {{Custom-size, functional, and durable DNA origami with design-specific scaffolds}}, doi = {10.1021/acsnano.9b01025}, volume = {13}, year = {2019}, } @article{6566, abstract = {Methodologies that involve the use of nanoparticles as “artificial atoms” to rationally build materials in a bottom-up fashion are particularly well-suited to control the matter at the nanoscale. Colloidal synthetic routes allow for an exquisite control over such “artificial atoms” in terms of size, shape, and crystal phase as well as core and surface compositions. We present here a bottom-up approach to produce Pb–Ag–K–S–Te nanocomposites, which is a highly promising system for thermoelectric energy conversion. First, we developed a high-yield and scalable colloidal synthesis route to uniform lead sulfide (PbS) nanorods, whose tips are made of silver sulfide (Ag2S). We then took advantage of the large surface-to-volume ratio to introduce a p-type dopant (K) by replacing native organic ligands with K2Te. Upon thermal consolidation, K2Te-surface modified PbS–Ag2S nanorods yield p-type doped nanocomposites with PbTe and PbS as major phases and Ag2S and Ag2Te as embedded nanoinclusions. Thermoelectric characterization of such consolidated nanosolids showed a high thermoelectric figure-of-merit of 1 at 620 K.}, author = {Ibáñez, Maria and Genç, Aziz and Hasler, Roger and Liu, Yu and Dobrozhan, Oleksandr and Nazarenko, Olga and Mata, María de la and Arbiol, Jordi and Cabot, Andreu and Kovalenko, Maksym V.}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {colloidal nanoparticles, asymmetric nanoparticles, inorganic ligands, heterostructures, catalyst assisted growth, nanocomposites, thermoelectrics}, number = {6}, pages = {6572--6580}, publisher = {American Chemical Society}, title = {{Tuning transport properties in thermoelectric nanocomposites through inorganic ligands and heterostructured building blocks}}, doi = {10.1021/acsnano.9b00346}, volume = {13}, year = {2019}, } @article{10362, abstract = {Nuclear pore complexes (NPCs) form gateways that control molecular exchange between the nucleus and the cytoplasm. They impose a diffusion barrier to macromolecules and enable the selective transport of nuclear transport receptors with bound cargo. The underlying mechanisms that establish these permeability properties remain to be fully elucidated but require unstructured nuclear pore proteins rich in Phe-Gly (FG)-repeat domains of different types, such as FxFG and GLFG. While physical modeling and in vitro approaches have provided a framework for explaining how the FG network contributes to the barrier and transport properties of the NPC, it remains unknown whether the number and/or the spatial positioning of different FG-domains along a cylindrical, ∼40 nm diameter transport channel contributes to their collective properties and function. To begin to answer these questions, we have used DNA origami to build a cylinder that mimics the dimensions of the central transport channel and can house a specified number of FG-domains at specific positions with easily tunable design parameters, such as grafting density and topology. We find the overall morphology of the FG-domain assemblies to be dependent on their chemical composition, determined by the type and density of FG-repeat, and on their architectural confinement provided by the DNA cylinder, largely consistent with here presented molecular dynamics simulations based on a coarse-grained polymer model. In addition, high-speed atomic force microscopy reveals local and reversible FG-domain condensation that transiently occludes the lumen of the DNA central channel mimics, suggestive of how the NPC might establish its permeability properties.}, author = {Fisher, Patrick D. Ellis and Shen, Qi and Akpinar, Bernice and Davis, Luke K. and Chung, Kenny Kwok Hin and Baddeley, David and Šarić, Anđela and Melia, Thomas J. and Hoogenboom, Bart W. and Lin, Chenxiang and Lusk, C. Patrick}, issn = {1936-086X}, journal = {ACS Nano}, keywords = {general physics and astronomy}, number = {2}, pages = {1508--1518}, publisher = {American Chemical Society}, title = {{A Programmable DNA origami platform for organizing intrinsically disordered nucleoporins within nanopore confinement}}, doi = {10.1021/acsnano.7b08044}, volume = {12}, year = {2018}, } @article{7285, abstract = {Hydrogelation, the self-assembly of molecules into soft, water-loaded networks, is one way to bridge the structural gap between single molecules and functional materials. The potential of hydrogels, such as those based on perylene bisimides, lies in their chemical, physical, optical, and electronic properties, which are governed by the supramolecular structure of the gel. However, the structural motifs and their precise role for long-range conductivity are yet to be explored. Here, we present a comprehensive structural picture of a perylene bisimide hydrogel, suggesting that its long-range conductivity is limited by charge transfer between electronic backbones. We reveal nanocrystalline ribbon-like structures as the electronic and structural backbone units between which charge transfer is mediated by polar solvent bridges. We exemplify this effect with sensing, where exposure to polar vapor enhances conductivity by 5 orders of magnitude, emphasizing the crucial role of the interplay between structural motif and surrounding medium for the rational design of devices based on nanocrystalline hydrogels.}, author = {Burian, Max and Rigodanza, Francesco and Demitri, Nicola and D̵ord̵ević, Luka and Marchesan, Silvia and Steinhartova, Tereza and Letofsky-Papst, Ilse and Khalakhan, Ivan and Mourad, Eléonore and Freunberger, Stefan Alexander and Amenitsch, Heinz and Prato, Maurizio and Syrgiannis, Zois}, issn = {1936-0851}, journal = {ACS Nano}, number = {6}, pages = {5800--5806}, publisher = {ACS}, title = {{Inter-backbone charge transfer as prerequisite for long-range conductivity in perylene bisimide hydrogels}}, doi = {10.1021/acsnano.8b01689}, volume = {12}, year = {2018}, } @article{14302, abstract = {One key goal of DNA nanotechnology is the bottom-up construction of macroscopic crystalline materials. Beyond applications in fields such as photonics or plasmonics, DNA-based crystal matrices could possibly facilitate the diffraction-based structural analysis of guest molecules. Seeman and co-workers reported in 2009 the first designed crystal matrices based on a 38 kDa DNA triangle that was composed of seven chains. The crystal lattice was stabilized, unprecedentedly, by Watson–Crick base pairing. However, 3D crystallization of larger designed DNA objects that include more chains such as DNA origami remains an unsolved problem. Larger objects would offer more degrees of freedom and design options with respect to tailoring lattice geometry and for positioning other objects within a crystal lattice. The greater rigidity of multilayer DNA origami could also positively influence the diffractive properties of crystals composed of such particles. Here, we rationally explore the role of heterogeneity and Watson–Crick interaction strengths in crystal growth using 40 variants of the original DNA triangle as model multichain objects. Crystal growth of the triangle was remarkably robust despite massive chemical, geometrical, and thermodynamical sample heterogeneity that we introduced, but the crystal growth sensitively depended on the sequences of base pairs next to the Watson–Crick sticky ends of the triangle. Our results point to weak lattice interactions and high concentrations as decisive factors for achieving productive crystallization, while sample heterogeneity and impurities played a minor role.}, author = {Stahl, Evi and Praetorius, Florian M and de Oliveira Mann, Carina C. and Hopfner, Karl-Peter and Dietz, Hendrik}, issn = {1936-086X}, journal = {ACS Nano}, number = {10}, pages = {9156--9164}, publisher = {American Chemical Society}, title = {{Impact of heterogeneity and lattice bond strength on DNA triangle crystal growth}}, doi = {10.1021/acsnano.6b04787}, volume = {10}, year = {2016}, } @article{363, abstract = {Lead halide perovskite materials have attracted significant attention in the context of photovoltaics and other optoelectronic applications, and recently, research efforts have been directed to nanostructured lead halide perovskites. Collodial nanocrystals (NCs) of cesium lead halides (CsPbX3, X = Cl, Br, I) exhibit bright photoluminescence, with emission tunable over the entire visible spectral region. However, previous studies on CsPbX3 NCs did not address key aspects of their chemistry and photophysics such as surface chemistry and quantitative light absorption. Here, we elaborate on the synthesis of CsPbBr3 NCs and their surface chemistry. In addition, the intrinsic absorption coefficient was determined experimentally by combining elemental analysis with accurate optical absorption measurements. 1H solution nuclear magnetic resonance spectroscopy was used to characterize sample purity, elucidate the surface chemistry, and evaluate the influence of purification methods on the surface composition. We find that ligand binding to the NC surface is highly dynamic, and therefore, ligands are easily lost during the isolation and purification procedures. However, when a small amount of both oleic acid and oleylamine is added, the NCs can be purified, maintaining optical, colloidal, and material integrity. In addition, we find that a high amine content in the ligand shell increases the quantum yield due to the improved binding of the carboxylic acid.}, author = {De Roo, Jonathan and Ibáñez, Maria and Geiregat, Pieter and Nedelcu, Georgian and Walravens, Willem and Maes, Jorick and Martins, Jose and Van Driessche, Isabel and Kovalenko, Maksym and Hens, Zeger}, issn = {1936-086X}, journal = {Nano}, keywords = {NMR, CsPbBr3, absorption coefficient, surface chemistry}, number = {2}, pages = {2071 -- 2081}, publisher = {American Chemical Society}, title = {{Highly dynamic ligand binding and light absorption coefficient of cesium lead bromide perovskite nanocrystals}}, doi = {10.1021/acsnano.5b06295}, volume = {10}, year = {2016}, }